This invention relates to an air-conditioning and heating unit for automotive vehicles.
Conventional air conditioning and heating units include a blower, an evaporator, a heat exchanger, air mixing flaps and air distribution flaps all disposed within a synthetic resin housing. The air mixing flaps and air distribution flaps serve to guide the air into desired discharge channels, i.e., into a center plane, a headroom plane, a footroom plane and a defroster.
Many such air conditioning and heating units in automotive vehicles are provided with additional throttles, as described in U.S. Pat. No. 4,549,692, as well as air guiding elements and flow stabilizers, in order to maintain the same air volume distribution and the same air discharge temperatures in the air outlet openings of the air conditioning and heating unit.
In such air conditioning and heating units, production of the housings is very expensive and the installation of the additional elements required is often difficult. Moreover, each unit produced is suitable for one type of vehicle only, while the additional elements frequently lead to undesired noise levels.
An object of the present invention is to provide an improved air conditioning and heating unit of the above-described type.
Another object of the present invention is to provide such an improved air conditioning and heating unit which is easy and inexpensive to manufacture.
A further object of the present invention is to provide such an air conditioning and heating unit which may be installed in more than one type of vehicle.
Yet another object of the present invention is to provide such an air conditioning and heating unit which is relatively quiet during operation.
Another, more particular, object of the present invention is to provide such an air conditioning and heating unit wherein the same air temperatures and the same air volumes are obtained in all inlet openings of various air discharge outlets or ducts, regardless of dimensions and without the use of air guidance elements.